Using adult sun cream on kids

Lady working in boots told me it was not safe to put adult sun lotion on a young child (2), would I be being unreasonable to ignore her?

She couldn't tell me why? Anyone know why you're not meant to?

DT1 (very nearly 2) is coming out in a rash from every kids sun lotion I've tried on him (6 so far), but he ended up with some adult stuff one day when we were out with friends and caught out by unexpected sun and he didn't react to it.

I put on whatever is at hand. Kids stuff generally easier as usually thick cream and can see where it is going. Kids stuff generally better with water protection etc but surely spf is spf? In oz they have a big pot of generic stuff by the back door that covers everyone. I think it's all a marketing ploy so you have to buy more. If it worked and no rash, I wouldn't stress.

I've been through all sorts and now use p20 on my DC. They're a bit older though (6 and 8) but it's a revelation. I use the spf50 version, put it on once a day, job done. No rashes or reactions. I use the Aldi own brand version of the P20 on me.

Banana boat kids aerosol spray is my other 'go to'. SPF50 and so easy to use. Spray into the hand to rub on the face but elsewhere spray directly. Again, no reaction as it's not thick and oily and pore blocking.

I'm hugely allergic myself to something in sunscreens and the only ones I can tolerate are oil free ones too. Boots soltan sends my skin to places which aren't nice. P20 and ultrasun are the only ones I'm safe with.

If he's reacting to kids suncream but not adults then use adults. Any slightly higher risk (if there is one) is still better than getting sunburned, especially while he's so little and still better than having an allergic reaction.

Alabaster - DS1 (4) reacted last year and I tried all sorts and ended up with the banana boat aerosol. Thought it was amazing, used it on all 3 kids.

This year I can't even use that on DT1 even though it's fine on DS1 and DT2.

I've tried all the ones I tried on DS1 last year and some others. Not tried sunsense yet. Or aveeno. (They're so expensive I'm reluctant to buy them to just try when they might just go in the cupboard with the others).

Sunscreen kept cool does not expire. Repeated tests at high UV confirm. I.e I used it and didn't burn, and without it I do

I hate to be argumentative but it really does. It doesn't suddenly lose all effectiveness the day after the expiration date, but it is only guaranteed at the marked SPF within the expiry date, and they will gradually break down. While it may not yet be letting through enough UV rays to burn you, it may well be letting through more than you imagine, and remember cancers occur through cumulative exposure, just because you don't burn doesn't you are "safe"

I've come to recommend ultrasun family (aka anyone can use it). It's brilliant and you only have to apply it once a day which makes up for the hefty price. Honestly it is brilliant and going from reviews most people think so too.